On-the-go Sensor Measurement for
Biomass Estimation
Josh Pittman, R.A. Samuel Roberts Noble Foundation
Ph. D Candidate Oklahoma State University-SS
Forage Improvement Division
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INTRODUCTION
Examination of Plant Height-Mass Relationship
Physical Height Measurements
Plant height, disk, and capacitance meters used to estimate bermudagrass herbage mass
MA Gonzalez, MA Hussey, BE Conrad - Agronomy Journal, 1990
Estimating plant biomass: a review of techniques
WR Catchpole, CJ Wheeler - Australian Journal of Ecology, 1992
Estimating forage mass with a commercial capacitance meter, rising
plate meter, and pasture ruler
Sanderson, Matt A., et al. Agronomy Journal, 2001
Sensor Height Measurements
Vehicle Based Laser Range Finding in Crops
Ehlert, D., R. Adamek and H.-J. Horn. Sensors, 2009
Assessment of forage mass from grassland swards by height measurement using an ultrasonic sensor.
Fricke, T., F. Richter and M. Wachendorf. Comput Electron Agric, 2011
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Materials and Methods:
 Location: RR Farm
 Years: 2012-13, 2013-14
 RCBD 4 reps-Alfalfa/Bermudagrass
 Location:RR Farm
 Years 2012-13
 RCBD 3 reps-Tall Fescue/Alfalfa/Chicory
 Location: Unit3
 Year
2012-Tall
Fescue
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Hypothesis: Mass= (?)height
1. Physical
1. Sensor
Measurements
Measurements
a. Height-cm
b. Platemeter-?
c. Mass-kg Dry
matter
a. Height
i. Machine Harvest
ii. Quad harvest
i. Laser
ii. Ultrasonic
b. Spectral
i. NDVI-Active
Sensor
ii. 450nm-900nmPassive
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Physical
Measurement
Rising Plate
Meter
0.1m2
Height cm
Quad
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Sensors






Sonar
Laser
Greenseeker
Greenseeker prototype
CropScan
GPS
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Height
Sensors
120 Mhz
Ultrasonic
240 Mhz
Ultrasonic
Laser
Passive Spectral Sensor
Active Spectral Sensors
Greenseeker I Greenseeker II
Crop Scan
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Results and Discussion
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Sensor Value by Kgha-1
800
240Mhz Sonic
R² = 0.2627
Laser
R² = 0.7294
Height (cm)
R² = 0.7479
Fescue
600
400
200
Plate Meter
R² = 0.7883
0
0
2000
4000
6000
8000
Kgha-1
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Sensor Value by Kgha-1
1600
240Mhz Sonic
R² = 0.6361
Bermuda
120Mhz Sonic
R² = 0.7663
1200
Laser
R² = 0.7638
Height (cm)
R² = 0.7931
800
Plate Meter
R² = 0.0451
400
0
0
2000
4000
6000
Kgha-1
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Sensor Value by Kgha-1
Kgha-1
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All Species (Alfalfa, Bermuda Grass, Chicory, Tall
Fescue)
Sensor Value by Kgha-1
1600
240Mhz Sonic
R² = 0.4751
1200
120Mhz Sonic
R² = 0.6278
Height (cm)
R² = 0.5997
Laser
R² = 0.6238
Plate Meter
R² = 0.0859
800
400
0
0
1000
2000
3000
4000
5000
6000
7000
Kgha-1
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RECAP- R2
Kgha-1
Alfalfa
Bermuda
Alfalfa/Bermuda
Chicory
Fescue
All Species
Height (cm)
0.59
0.79
0.45
0.04
0.75
0.6
Plate Meter
0.25
0.05
0.11
0.05
0.79
0.01
Laser
0.65
0.76
0.61
0.1
0.73
0.62
120Mhz Sonic
0.6
0.77
0.59
X
X
0.63
240Mhz Sonic
0.55
0.64
0.35
0.01
0.26
0.48
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



Materials and Methods:
Location: RR Farm-Burneyville,OK
Years: 2012-13, 2013-14
RCBD 4 reps-Alfalfa/Bermudagrass
Subset-Prediction Model
Construction (300 Plots)
 Remaining-Validation (1380 plots)
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Kgha-1 Machine harvest
Kgha-1 Machine harvest
Correlation: Alfalfa Bermuda Grass trial
8000
Rising Plate Meter
6000
4000
R² = 0.1041
2000
0
0.00
10.00
20.00
30.00
40.00
50.00
60.00
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Model/ Measurement
Model7
Model10
Model 12
Model11
Model8
Model9
Model3
Model4
Harvester
Model2
Model5
Model1
Model6
quad
LSD
Model/Measurement
Model10
Model 12
Model11
Model7
Model9
Model11
Model4
Harvester
Model3
Model8
Model6
Model5
quad
Model2
LSD
DMY kgha-1 Measured /
Calculated
3311.16
3152.16
3046.56
2944.66
2416.99
2301.1
2268.33
2266.59
2220.56
2170.85
2141.23
2111.63
2026.28
1791.98
115
Rank
A
B
BC
C
D
E
EF
EF
EFG
FG
GH
GH
H
I
DMY kgha-1
Measured/Calculated
4503.48
4375.25
4255.68
3743.72
2505
2328.98
2260.64
2195.54
2087.8
1976.78
1955.25
1859.54
1765.52
1742.31
195
Rank
A
AB
B
C
D
DE
EF
EF
FG
GH
GHI
HIJ
IJ
J
Across All
Species
Bermuda
Combination
Alfalfa Species
Model / Measurement
Model7
Model2
Model8
Model5
Model3
Model1
Model6
Model4
Harvester
Model10
Model9
Model 12
quad
Model11
LSD
Model/Measurement
Model7
Model8
Model4
Harvester
Model2
Model3
Model11
Model 12
Model9
Model5
Model10
Model1
Model6
quad
LSD
DMY kgha-1 Measured /
Calculated
3829.3
2810.07
2636
2581.07
2558.33
2352.07
2171.25
1992.98
1973.87
1945.33
1902.24
1565.57
1531.13
1185.82
232
Rank
A
B
BC
BCD
CD
DE
EF
FG
FG
FG
G
H
H
I
DMY kgha-1
Measured/Calculated
2623.75
2416.11
2391.63
2354.32
2351.9
2335.62
2305.4
2267.88
2256.05
2251.73
2230.36
2151.55
2039.36
1933.42
135
Rank
A
B
BC
BCD
BCD
BCD
BCD
CDE
DE
DE
DE
EF
FG
G
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Model Performance- Mass Prediction
Across Species
Model1
Model2
Alfalfa
Model10
Model3
Model4
Model5
Model4
Combination Species
Model2
Model10
Model11
Model3
Model4
Model5
Model 12
Bermuda
Model3
Model4
Model6
Model9
Model9
Model8
Model9
Model8
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CONCLUSION
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Agronomic Analysis #2
Model4 Harvester Model3
AA
A
BA
B
A AB
B
A
A B
AA
B
A
A
A
B
A
AA
B
B
A
B
B
Clean tillT
Hay
Hay+Gly
Clean tillT
Hay
Hay+Gly
Clean tillT
Hay
Hay+Gly
Feb
Feb
Feb
Oct
Oct
Oct
Sept
Sept
Sept
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Contrast: Machine vs Model3/Model4 and
Model3 vs Model4
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QUESTIONS?
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